1221143564 has 12 divisors (see below), whose sum is σ = 2137288104. Its totient is φ = 610489824.

The previous prime is 1221143551. The next prime is 1221143587. The reversal of 1221143564 is 4653411221.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23552 + ... + 54744.

It is an arithmetic number, because the mean of its divisors is an integer number (178107342).

Almost surely, 2^1221143564 is an apocalyptic number.

It is an amenable number.

1221143564 is a deficient number, since it is larger than the sum of its proper divisors (916144540).

1221143564 is a wasteful number, since it uses less digits than its factorization.

1221143564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40984 (or 40982 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 1221143564 is about 34944.8646298709. The cubic root of 1221143564 is about 1068.8634871268.

Adding to 1221143564 its reverse (4653411221), we get a palindrome (5874554785).

The spelling of 1221143564 in words is "one billion, two hundred twenty-one million, one hundred forty-three thousand, five hundred sixty-four".